In recent years, a display device that performs reflective display (hereinafter referred to as “reflective display device”) is used for electronic paper and the like. Here, the reflective display is a display method in which an external light is reflected to display an image, and examples thereof include a reflective liquid crystal display method, a cholesteric liquid crystal display method, an electrowetting display method, an electrophoretic display system, and an electronic liquid powder display system and the like.
Compared with a transmissive display device having a backlight, the reflective display device has the low power consumption since it does not have a backlight. In addition, compared with a self-luminous display device such as an EL (Electro Luminescence) display, the reflective display device is further advantageous in low power consumption since it has an image holding memory property. In addition, since a sharp image can be visually recognized on the reflective display device without deterioration of visibility under strong external light such as sunlight, which is the biggest disadvantage of the transmissive display device and the self-luminous display device, the device is excellent in the conditions under which it is used outdoors. On the other hand, there is a feature that it is difficult to obtain high reflection luminance under a limited external light such as indoors and the visibility is deteriorated.
When a user (observer) using the reflective display device views the screen with a reflective display device, for example, a tablet terminal or the like, the user (observer) basically views the tablet terminal in a manner that the user (observer) and the tablet terminal or the like face each other according to the user (observer) posture.
Further, in the reflective display device, conventionally, since visibility is easily influenced by the intensity of external light, it is common to provide a diffusion layer (diffusion film) capable of improving the reflectance of light. For example, provided is a device in which a diffusion layer (diffusion film) is arranged on the viewing side of a display device (for example, Patent Literature 1).